There are numerous possibilities for applying antiperspirant compositions to the skin. Stick compositions having a stable shape are spread over the skin using a stick dispenser until an effective amount has been applied. Gels and creams can also be applied with stick-type dispensers, which are applied to the skin using a dispenser surface. For antiperspirant and/or deodorant compositions for the axillary area in particular, numerous different forms of application have been developed, mainly sprays and roll-on compositions that contain propellant gas and those that are free of propellant gas, in addition to those already mentioned. In the case of roll-on preparations that are free of propellant gas, a slightly thickened fluid is applied by means of a rotatably mounted ball by rolling it over the skin. Antiperspirant roll-on compositions may be water-based or oil-based. For example, the oil-based preparation of the usual antiperspirant sprays is also suitable for administration as a roll-on preparation. In this case, the antiperspirant active ingredient is in the form of a powder suspended in oil, the oil being thickened with a lipophilic gelling agent to prevent separation of the powder particles. However, such roll-ons are hardly represented in the market. The usual antiperspirant roll-on compositions are water-based, i.e., they contain water in an amount of approx. 50 wt % or more, based on their total weight. The antiperspirant active ingredient, usually an antiperspirant aluminum or aluminum zirconium compound, is present in dissolved form.
The hygiene routine of many users includes regular shaving of the underarm area before applying an antiperspirant or deodorant, but application of an ethanol-based agent to freshly shaved skin can cause a great deal of burning. With regular use, such agents dry the skin and thus make it more sensitive and easily irritated.
WO 2013/105924 A2 discloses an anhydrous oral hygiene composition containing a zirconium-amino acid complex, for example, a zirconium-alanine complex, which is suspended in a hydrophobic vehicle and is suitable for treatment of hypersensitive teeth.
EP 1161589 B1 discloses a liquid deodorant with a high deodorizing effect, which is at the same time gentle on textiles and contains 80 to 99 wt % water, 0.1 to 2.0 wt % of a component comprising quaternary ammonium groups or amine oxide groups and one or two C8-C22 alk(en)yl groups in the molecule, and a buffer solution, which is adjusted with an acid that may be valine and an alkalizing agent to a pH in the alkaline range of 7.5 to 9.5. However, antiperspirant compositions containing highly effective aluminum zirconium compounds must have an acidic pH, preferably a pH in the range of 3.0 to 4.5, especially preferably in the range of 3.4 to 4.0, measured at 20° C. In the neutral and alkaline range, the aluminum zirconium compounds would hydrolyze to form less active hydroxides.